Generally, a bracelet can be adjusted into predetermined positions which allow for precise repositioning, and which the user can adjust through the cooperation of a finger with one among a plurality of holes, or by hooking a pin onto a rack, or a similar device. Fastenings of the continuous type, maintained in position by friction, do not offer the possibility of precise repositioning.
There is known from CH Patent No 699067 a device for finely adjusting the length of a bracelet incorporated in a clasp cover, and comprising a device for indexing in two predefined positions, and which includes spring ball push buttons which are integral with a transverse bar, connected to one end of the bracelet and arranged to cooperate with holes provided in the clasp cover.
This device acts transversely, generally requires a tool to perform the adjustment, and remains visible.
There is also known from EP Patent 2484244 an adjustable link for bracelets, including at least a first half link and at least a second half link arranged to be movably assembled in relation to each other in a longitudinal direction of the bracelet, with a mechanism that can be adjusted without any particular tools, wherein the adjustment mechanism remains concealed.
This device does not permit a fine continuous adjustment of the position of the half-links and allows an opening to be seen in the connecting piece between the half-links, which detracts from the appearance of the bracelet. Further, the link can come undone in the event of a shock, since there is nothing to ensure that the adjustment is reliably locked.